Comparing calorimetric and dielectric polarization modes in viscous 2-ethyl-1-hexanol.
Comparing calorimetric and dielectric polarization modes in viscous 2-ethyl-1-hexanol.
复制标题
DOI：
10.1063/1.2539105
复制
发表时间：
2007-03
期刊：
影响因子：
--
通讯作者：
H. Huth;Li-Min Wang;C. Schick;R. Richert
中科院分区：
文献类型：
--
作者：
H. Huth;Li-Min Wang;C. Schick;R. Richert
比较了2-乙基-1-己醇在玻璃化转变温度Tg附近的介电弛豫和动态热容测量值，以进一步阐明在许多单羟基醇和其他氢键液体中观察到的突出的debye型损失峰的起源。当介电谱epsilon“显示出两个不同的极化过程，它们在峰值频率方面相隔2000倍，而热容量cp”只显示出一个峰值。低幅值和高峰值频率的介电过程与量热信号重合，而大介电德拜信号与量热模无关。作者得出结论，德拜过程对应于只有在外加电场的情况下能量不同的状态之间的跃迁。
Dielectric relaxation and dynamic heat capacity measurements are compared for 2-ethyl-1-hexanol near its glass transition temperature Tg in order to further clarify the origin of the prominent Debye-type loss peak observed in many monohydroxy alcohols and other hydrogen-bonding liquids. While the dielectric spectrum epsilon" displays two distinct polarization processes that are separated by a factor of 2000 in terms of the peak frequency, the heat capacity cp" shows only a single peak. The dielectric process with lower amplitude and higher peak frequency coincides with the calorimetric signal, whereas the large dielectric Debye signal is not associated with calorimetric modes. The authors conclude that the Debye process corresponds to a transition among states which differ in energy only in the case of an external electric field.